Coffee maker



mac. 10, 1940. H. G. DAVIS COFFEE MAKER Filed July 24, 1939 2 Sheets-Sheet l INVENTOR.

. ATTORNEY.

mini-in l I I H" In illm Patented Dec. 10, 1940 UNITED STATES PATENT; OFFICE...

COFFEE MAKER I Harold G. Davis, Denver, 0010. Application July 24, 1939, sci-mm. 286,221

7 Claims. (01. 53-3) sible for any vapor or aroma to escape from the 6 time brewing starts until the cofl'ee reaches the cup; in which the ground cofiee will not be sub- Jected to boiling; in which a complete and thorough brewing action will be obtained; and in which the final coiiee will be free from grounds.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and emciency. These will become more apparent from the following description.

In the following detailed description of the invention reference is had to the accompanying drawings which form a part hereof. Like numerals refer to like parts in all views of the drawings and throughout the description.

. In the drawings:

Fig. 1 is a side elevation of the assembled coffee maker.

Fig.2 is a vertical section through the cofiee ,maker, in the position of Fig. 1, as it would appear when the brewing is completed and th cofiee is ready for pouring.

31s a side elevation partially broken away "ulfi'strsjt'lii'gftiie c'oifee maker'intne preliminary cap for holding the compositloii' 'fingerknob in point.

- Fig. 4 is a fragmentary horizontal'cross section therethrough, taken on the line it-4i, Fig. 3.

Fig. 5 is 'a small scale side elevation, partially in section, illustrating the coffee maker in an intermediate position.-

Fig. 6 is an enlarged detail section through the upper edge of the outer container illustrating a lug of the inner container resting thereon.

Fig. fl is a detail perspective View of the metal place.

The improved coifee maker comprises an open topped outer container It, preferably but not necessarily of pyrex or other heat resisting glass. The upper edge of the outer container it is turned inwardly to form a slightly restricted neck portion l l. Two vertical passageways l2 extend downwardly through the restricted neck portion and a spout l3 is also formed therein.

The container I0 is formed with two circumferentlal, spaced-apart beads 22 for holding a handle band 23 in place thereon. The extremities o! the handle band are secured to a suitable handle 24 by means of clamp screws 25 which clamp the band 23 snugly around the contain-. er l0.

An open'bottomed inner container l4, also 6 preferably of glass, fits telescopically into the outer container Ill. The inner container I4 is formed with three projecting lugs 15 which normally support the inner container above the outer container, as shown in Fig. 3. When the 10 inner container is turned to a. certain position these three lugs aligmwith the two passages l2 and the spout it so that they can' pass down- 'wardly through the restricted portion M to the position shown in Figs. 1, 2,and 5. The con- 15 tainers m and it are imperforate.

The closed top of the inner container M is formed with a-bulbous projection it for the attachment of a linger knob ll of bakelite or. similar non-metallic material. The knob is at- 20. tached by means of a resilient metal clamping cap it, the skirt of which is split at a plurality of points, as shown at 33, so that it can expand to snap into place and 'into gripping engagement about the projection l6. The knob ll was placed over the cap it resting ag'ainsta resilient gasket it. A screw 26 is then threaded through the knob ll, into an internally threaded boss 36 'on the cap it, to pull the knob securely against the gasket it. After the knob ll is in place, the 80' 'oapcahnot'he pulled irom the projection l6 since positionfor---.bringing the waterto the .hoilin j' sealants, str ngently ql se rev t xoansion of-thecap. j

- The bottom of the innercontainer M is slightly reduced in diameter and is formed with a series. of projecting, inclined thread lugs ii. In the construction illustrated, four of theinclined lugs:

are employed.

A convex spider member 26 is detachably secured across the open bottom ofthe container is. The spider member is formed with a peripheral band from which four hooked members 22 arena? The hook masters- 21 correspond in number and position to, the thread-lugs 2| and, when the spider member is' rotated, these hooks 5 slide upwardly over the lugs to clamp the spider member tightly against the bottom edge of the container id. i The spidermember supports an outer tube 28' which extends axially upwardly into the inner 5t container ll. An annular filter medium it is clamped between the lower edge of the inner container and the spider member 26 and rests upon the latter to close the bottom of the contamer it. 6B

is brought to the boiling point.

Any suitable material may be used for the filter medium 29 It has been found that a rough surface, porous fabric, such as turkish toweling, is admirably adapted for this purpose since it prevents surface washing action when pouring and holds the coffee grounds uniformly distributed thereover so that the grounds themselves serve as a filter bed.

A percolater tube 30 having a bell-shaped bottom 3| rests upon the bottom of the outer container ID. The tube 30 is of smaller diameter than the tube 28 and extends upwardly therein leaving an open passage between the-two tubes. The bell-shaped bottom 3] is received in the concave spider member 26 when theassembly is in the position of Fig. 2. A series of knobs 32 project downward from the spider member so as to support the latter above the bottom of the container. Ill when in the position of Fig. 2.

Operation The water is placed in the outer container l0 and the innercontainer I4 is held on its side and container I4 is now placed in the outer container ID, as illustrated in Fig. 3with the lugs l5 supporting it above the waterline therein. The complete assembly is then placed on a stove or other heating device and the water in the container l0 The heat at the bottom of the percolator tube forces hot vapor and steam up the tube 30 into the inner container ll thereby filling the interior with hot, expanded vapor or steam to exhaust the air therefrom. Any bubbling water overflowing the percoiator tube flows downwardly between the two tubes into the water in the container l0 so that the ground coffee remains dry. Thisaction I creates a slight pressure in the container II to container It. The latter-graduallydescends as lowering temperature of the water.

force the cool air downwardly through the ground coffee and through the filter 29 and discharging it above the water in the container l0.

Thecomplete assembly, is now removed from the fire, the inner container I4 is rotated to align the lugs IS with the passages l2 and the spout l3, and it is lowered onto the surface of the water in the container II), as shown in Fig. 5. The inner container temporarily floats in this position until a reduction in pressure occurs therein, due to .the The cooling of any air remaining in the inner container and the condensation of the steam and vapor thereincreates a partial vacuum which draws the water from the outer container l0 upwardly through the filter and through the ground coffee into the inner it fills until. it reaches the position of Fig. 2 at which time the vacuum will continue to'draw the water from the outer container until it is all completely within the inner container, as.shown' in Fig. 2. a

When the outer container It has been exhausted of water, air passes between the filter This percolating action continues at intermittent intervals as long as there is suflicient heat present and causes a definite circulation and brewing action downwardly through the ground coffee and upwardly between the tubes so as to extract the maximum strength therefrom. 1

The coffee remains in the inner container until ready for use. It is poured into the coffee cup from the position of Fig. 2. When the containers are tilted for pouring, air enters the inner container through the upper side of the space between the tubes 28 and 30 to displace the cofiee which fiows downwardly through the grounds and filter medium, between the spider member 26 and the bell-shaped bottom 3|, into the outer container l0 and from the spout [3 thereof.

The bell-shaped bottom 3| serves to separate a portion of the water over the hot spot in the bottom from the remainder of the water so that'this water will reach boiling temperature in advance of the remainder of the water so as to increase the speed of evacuation from the inner container l4.

The lugs i 5 cooperate with the in-tumed upper edge I I of the outer container to form. guide mem- 'bers to maintain the inner container vertical an to prevent tilting 'or cramping thereof.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is: 1. A coilee maker comprising: an open topped outer water container; an open bottomed inner container vertically movable in said outer container, said containers being hermetically sealed except for their respective open top and bottom: I

a filter support detachably-secured across the bottom of said inner container: a filter medium supported by said filter support: and a percolating tube extending upward from the bottom of said outer container through said filter support and through said filter medium and terminating within said inner container.

2. A coffee maker comprising: an open topped outer water container: an open bottomed inner container vertically movable 'in said outer container, said containers being hermetically sealed except for, their respective open top and bottom; a filter support detachably secured across the bottom of said inner container; afilter medium supported by said filter support; a percolating tube extending upward from the bottom of said outer container through said filter support and through said filter medium and terminating within said inner. container; and releasable means for supporting the inner container above the water line outer water container; an open bottomed inner container vertically movable in said outer container, said containers being hermetically sealed except for their respective open top and bottom';

a filter support detachably-secured across the bot-' tom of said inner container; a filter medium s'upported by 'said filter support; a percolating tube extending upward from the bottom of said outer container through said filter support and through said filter medium. and terminating within said inner container; and an outer tube extending upward from said filter support into saidinner c0ncontainer vertically movable in said outer container, said containers being'hermetically sealed except for their respective opentop and bottom; a filter support detachably secured across the bottom of said inner container; a filter medium supported by said filter support; a percolating tube extending upward from the bottom of said outer container through said filter support and through said filter medium and terminating within said inner container; an outer tube extending upward from said filter support into said inner container about said percolating tube; and releasable means for supporting the inner container above the water line in the outer container until released.

5. A coffee maker comprising: an open topped outer water container; an open bottomed inner container vertically movable in 'said outer container, said containers being hermetically sealed except for their respective open top and bottom; a filter support detachably secured across the bot- 1 tom of said inner container; a filter medium supported by said filter support; a fixed outer tube extending axially upward in said inner container from said filter support; and a loose percolator tube having a belled-bottom resting on thebottom of said outer container and extending upward past said filter medium and terminating within said outer tube.

6. A cofiee maker comprising: an open topped outer water container; an open bottomed inner container vertically movable in said outer container, said containers being hermetically sealed except for their respective open top and bottom; a filter support detachably secured across the bottom of said inner container; a filter medium supported by said filter support; a fixed outer tube extending axially upward in said inner container from said filter support; a loose percolator tube having a belied-bottom resting on the bottom of said outer, container and extending upward past said filter medium and terminating within said outer tube; and releasable means for supporting the bottom of said inner container above the water line insaid outer container until released.

7. A coifee maker comprising: an outer water container having an inwardly extending upper peripheral edge; an open-bottomed inner container vertically movable within the confines of said edge; lugs projecting from said inner container and resting on said edge to support the lower edge of the inner container above the water line in the outer container; there being vertical passageways through said edge for said lugs to allow the inner container to be lowered into the outer container when desired; a spider member detachably secured across the bottom 01' the inner container; an axially positioned outer tube extending upward from the spider member into the inner container; 9. filter medium supported by the spider 'and closing the bottom of the inner container about said tube: a bell-shaped member resting on the bottom of said outer container; and a percolator tube extending upwardly through said bell-shaped member and terminating within said outer tube.

- a v HAROLD G. DAVIS. 

